1. Technical Field
The present invention relates to filters, and, more particularly, to a bi-flow filter which can be used in purifying water for swimming pools and other applications.
2. Description of Prior Art
Conventional filters used in the purification of swimming pool water have several shortcomings. For instance, they characteristically contain structures inside their main cavities which disrupt the water flow during filtration. These obstructions cause "dead spots" to form within the filter during operation. "Dead spots" are places within the filter on the downstream side of a flow obstruction where no filtering action takes place, thus decreasing filter efficiency and requiring a proportionately larger filter to handle a given filtering job. Besides detracting from filter efficiency, internal obstructions and their associated dead spots also provide places where bacteria are likely to grow.
A further shortcoming is that existing filters require the use of expensive heavy gauge materials for construction of the filter's walls and other necessary parts. Another shortcoming is that there is no way to visually or physically inspect the filter media during the backwash operation.
Still another shortcoming is that present control systems used with these existing filters are fairly complicated and require the operation of several valves in cycling from normal filtering operation to backwash operation and vice versa.
In light of the above shortcomings of existing swimming pool filters, a need exists for a swimming pool filter which is free from flow obstructions during filtration and has a minimum of obstructions during backwash. A need also exists for a filter which is inherently structurally strong, easier and more economical to construct. A further need exists for a filter which will permit the use of a relatively simple control system for cycling the filter operation between normal filtering operation and backwash operation.